Exhaust header



Oct. 7, 1969 THOMPSON 3,470,690

EXHAUST HEADER Filed on. 4. 19s? 7 4%,, L #122,122 W /%@A,

firraexveys Unlted States Patent 3,470,690 EXHAUST HEADER Marlon L.Thompson, 2734 Eastvale, Rolling Hills, Calif. 90274 Filed Oct. 4, 1967,Ser. No. 672,816 Int. Cl. F01n 1/00, 7/08 U.S. Cl. 60-32 9 ClaimsABSTRACT OF THE DISCLOSURE An exhaust header having tubes for connectionbetween the exhaust ports of an engine and the interior chamber of theexhaust collector, and characterized in that the downstream ends of thetubes are arranged within the collector chamber such that the effectivelengths of the air columns defined by the tubes is approximately equal.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates to an exhaust header for collecting and carrying away theexhaust products of an engine.

Description of the prior art Specially designed exhaust headers are usedin high performance racing and sports vehicle engines to improve theefficiency of such engines. More particularly, it has been establishedthat improved engine performance is achieved when the individual exhaustlines or tubes passing from the engine exhaust ports to the exhaustcollector are made substantially equal in length. However, this isextremely difiicult to accomplish. The tubes must fit between and aroundthe various engine components and accessories as they pass from theexhaust ports to the collector, and this often means that the bendsrequired in one tube make that tube longer than the others. Tocompensate for this disparity the designer must provide unnecessarybends in the other exhaust tubes. This provides the desired equal lengthexhaust header system, but a great deal of time and expense is necessaryto design the exact bends in the tubes, and in a manner which will fitthe bends to the equipment clutter around a particular engine. Eachexhaust header is thus a relatively expensive, highly individualizeditem.

SUMMARY OF THE INVENTION The present invention relates to an exhaustheader in which the exhaust gas conduits between the engine exhaustports and the exhaust collector project different distances into theinterior chamber of the exhaust collector.

It is theorized that the balance or tuning of an engine to provideoptimum efliciency or performance is dependent upon the degree to whichthe designer is successful in equalizing the respective contributions tosuch performance by the several cylinders. For example, in an internalcombustion engine utilizing a carburetor, the air entering thecarburetor, the air-fuel mixture entering the cylinders, and the exhaustdischarged from the cylinders, collector, muffler and exhaust pipe areall part of a complex system of air columns defined by the respectivecomponents through which these various fluids flow.

Disturbances in these air columns are propagated as condensations andrarefactions, a disturbance at one end traveling to the other end, beingreflected, traveling back, and so on. Stationary waves are set up in thecolumns. If the lengths of the air column are not properly tuned, theengine designer may find, for example, that at certain frequencies ofinlet valve operation the air-fuel mixture is thrust out of thecarburetor, or he may find that at certain frequencies of exhaust valveoperation the exhaust gases pass freely through certain of the exhaustlines or tubes but that the lengths of the other tubes are such thatpassage of exhaust gases into such tubes is bucked or resisted.

The present invention is concerned with adjustment of the lengths of theair columns downstream of the engine exhaust ports. Ideally, suchlengths are adjusted so that the air columns vibrate at a frequencyproviding rarefactions at the engine exhaust ports approximately at thetimes of opening of the exhaust valves. Moreover, such lengths should beadjusted so that the exhaust tubes each have an approximately equaleffect in carrying away the exhaust gases. Of course, the invention alsoenables adjustments providing unequal lengths if such is desirable forany reason.

An object of the invention is to permit the exhaust tubes of an exhaustheader to be formed or configured in a manner best suited to connect thetubes to the engine and fit them in and about the engine components andaccessories, and without regard to the disparate physical length of theair columns defined by the irregularly shaped tubes. Then, the lengthsof the air columns are adjusted by adjusting the distance which eachtube projects into the interior chamber of the exhaust collector.

The collector chamber is of relatively large volume compared to that ofeach exhaust tube so that discharge of gases into the chamber isgenerally equivalent to discharge of such gases into open space.Consequently, once the tubes have been fitted in optimum fashion to theengine, the disparities in length are corrected by projecting the tubesinto the collector chamber the requisite distances.

Another object of the invention is to provide a set of adapter tubes ofproper lengths to tune the air columns of the main exhaust tubes, anddetachably mount these to the main tubes. This permits a dealer, forexample, to stock various sets of adapter tubes for tuning stock oroiT-the-shelf sets of main tubes for various engines. The set of adaptertubes is preferably made an integral part of the collector so thatinstallation of a set of adapter tubes is simply a matter of removingthe existing collector and installing the equal-length collector.

Other objects and features of the invention will become apparent fromconsideration of the following description taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of anexhaust header according to the present invention;

FIG. 2 is an enlarged and exploded perspective view of the exhaustcollector of the header of FIG. 1;

FIG. 3 is an enlarged side elevational view of the central portion ofthe header of FIG. 1;

FIG. 4 is a sectional view taken along the lines 44 of FIG. 3; and

FIG. 5 is a sectional view taken along the lines 55 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,there is illustrated an exhaust header 10 according to the presentinvention which is adapted for connection to the exhaust ports of anengine (not shown). The header 10 comprises, generally, an elongatedcollector 12 having an internal chamber 14; and a plurality of tubularconduits or assemblies 16.

As best illustrated in FIG. 1, each tubular conduit or assembly 16includes an elongated, irregularly configured main tube 18 and anadapter tube 20 which fits and pro jects within the collector 12. Eachmain tube 18 is welded or otherwise rigidly connected at its upper orupstream end to a mounting bracket 22. The bracket 22 is adapted to bebolted to the engine in overlying relation to the engine exhaust ports,and includes a plurality of openings to permit the exhaust gases fromthe engine exhaust ports to pass into the main tubes 18.

The tubes 18 are configured in a manner best adapted to fit the tubes 18in the space available within the engine compartment. The downstreamends of the main tubes 18 are welded or otherwise rigidly secured to aplate or flange 24 provided with a plurality of apertures aligned withthe ends of the tubes 18. The flange 24 includes openings for fastenersto facilitate securement of the collector 12 and tubes 20 to the tubes18, as will be seen. The lengths of the tubes 18, by virtue of theirregular configurations thereof, generally are not of equal length.Consequently, the air columns defined by the main tubes 18 are also ofunequal length.

As previously indicated, it has been found to be desirable to provideexhaust gas conduits or tubular assemblies 16 of substantially equallength to enhance the efficiency of performance of the engine with whichthe exhaust header is associated. In this regard, the phrase air columnis intended to include the gaseous or fluid column defined by theinterior walls of each tube 18, for example, and which terminatessubstantially at the ends of such tube 18.

The plurality of adapter tubes 20, which are part of the tubularassemblies 16, are usually of unequal length, as best shown in FIGS. 2,3, and 4. The adapter tubes 20 are wholly located within the collectorchamber 14 and are secured at their upstream ends to a plate or flange26 having apertures in alignment with the ends of the tubes 20.

The opposite or downstream ends of the adapter tubes 20 empty into therelatively large volume of the chamber 14, as best seen in FIG. 4, sothat the effect is analogous to termination of the adapter tubes 20 inopen space. As can be seen from the drawing, the axes of the tubes 20are generally parallel to the longitudinal axis of the chamber 14, sothat exhaust gases are discharged in the same general direction throughthe tubes 20 and through the chamber 14.

The flanges 24 and 26 to which the tubes 18 and 20 are welded,respectively, are engaged upon the opposite faces of a conventionalsealing gasket 28 which is suitably apertured to permit the flow ofexhaust gases from the tubes 18 into the tubes 20. The flanges 24 and 26are rigidly bolted together in fluid-tight relation by a plurality ofusual nut and bolt assemblies 30. The assembled main tubes 18 andadapted tubes 20 constituting the tubular assemblies 16 define aircolumns which are preferably of substantially equal length. Thegenerally unequal lengths of the tubes 18 are effectively made equal bycoupling to them adapter tubes 20 of appropriate length.

Preferably the tubes 20 which are welded to the flange 26 are made anintegral part of the elongated collector 12 by Welding of the upstreamend of the collector 12 to the downstream face of the flange 26, as bestseen in FIG. 4. With this arrangement, the disparate lengths of the maintubes 18 for various types of engines can quickly and easily be adjustedby substitution of a collector 12 incorporating adapter tubes 20 of theproper length. This greatly simplifies the stocking of parts andup-dating of existing engines.

The walls of the collector 12 defining the interior chamber 14 arepreferably dished or formed inwardly to occupy as much of the space aspossible which is defined by the exterior profile of the bunched orclosely arranged adapter tubes 20 which extend in parallel relation andaxial alignment with the collector 12.

The downstream extremity of the collector 12 is of circular crosssection and terminates in a plate or flange 32 similar to the flanges 24and 26. The flange 32 is adapted for securement by a plurality offastener assemblies 34 to a complemental flange 36 forming a part of theexhaust system leading to the muflier and tail pipe (not shown).

The foregoing arrangement also greatly facilitates welding of thetubular assemblies 16 to the collector 12. That is, by separating eachtubular assembly 16 into a main tube 18 and an adapter tube 20, the maintube 18 can quickly be welded to its flange 24, and the adapter tube 20welded to its flange 26. Weldment of the collector 12 to the flange 26is also a simple matter. All that remains is to secure together theassembly with the fastener assemblies 30. However, as previouslyindicated, the primary object of the invention is the provision oftubular assemblies 16 extending or projecting different predetermineddistances into the collector chamber 14 to thereby provide lengths oftubular assemblies 16 which heretofore were possible only byincorporating extra bends in certain of the tubes.

The adapter tubes 20 can be used not only to tune the exhaust side ofthe engine, that is, adjust the effective lengths of the conduits on theexhaust side, but also can be used to tune the intake side of theengine. For example, if an intake runner, which term is used to indicatethe airfuel line from the carburetor to the intake port of a particularcylinder, is pinched or sharply bent or for some reason is not providingthe same fluid flow as the other intake runners, the adapter tube 20corresponding to that runner can be adjusted in length to correct themalfunction of the intake runner. In this regard, it has been found thatshortening such an adapter tube 20 provides an eductor effect tending toencourage an increase in the rate of fluid flow through the associatedmain tube 18 and also through the associated intake runner.

Although the present invention has been referred to in connection withracing and sports vehicle engines, the invention is adapted for use withvarious other types of engines, including stationary and aircraftengines, as will be immediately apparent to those skilled in the art.

Referring now to FIGS. 1 and 5, an elongated air tube 38 having a bellmouth or flared end 40 is welded at its downstream end to the flange 24.This downstream end is in communication with complemental openings inthe flanges 24 and 26 and in the gasket 28. Fresh air entering theupstream end 40 of the air tube 38 can thus flow into the collectorchamber 14. The tube 38 can be configured (not shown) to locate the end40 in optimum position for receiving a flow of air.

The air tube 38 provides additional oxygen to the chamber 14 and otherdownstream exhaust components so that unburned charges present in theexhaust can be burned. Thus, with the addition of the tube 38, thecollector 12 can function as an afterburner. Moreover, a fuel line 42can also be attached to the tube 38, as illustrated, to feed or injectfuel into the tube 38 for mixture with incoming air, thereby enhancingthe combustion and afterburner effect. Afterburning not only improvesthe completeness of combustion, which is important in smog control, butalso appears to have an eductor effect on the exhaust emanating from theadapter tubes 20. That is, a low pressure area appears to be createddownstream of the tubes 20, which desirably facilitates discharge ofexhaust gases.

I claim:

1. An exhaust header for receiving gases from the ex- 9 haust ports ofan engine, said header comprising:

a collector having an elongated internal chamber; and a plurality oftubular means adapted at their upstream ends to receive exhaust gasesfrom separate ones of the engine exhaust ports, the downstream ends ofsaid tubular means being connected to said collector in communicationwith said chamber, a plurality of said downstream ends projecting intosaid chamber for dischange of said exhaust gases along axes generallyparallel to the longitudinal axis of said chamber, the projectingportions being of predetermined lengths and forms such that saidplurality of tubular means are characterized by air columns ofapproximately equal effective lengths.

2. An exhaust header according to claim 1 wherein said tubular meanscomprise a plurality of main tubes for connection at their upstream endsto said engine exhaust ports; a plurality of adapter tubes of differentlengths; and coupling means connecting said adapter tubes to saidcollector and to said main tubes, said adapter tubes being locatedwithin said chamber, and forming a continuation of said main tubes.

3. An exhaust header according to claim 2 wherein said coupling meansincludes: mating flanges on said main tubes and said adapter tubes; andmeans detachably fastening together said flanges whereby said adaptertubes can be quickly attached to said main tubes to adjust the lengthsof said air columns according to the lengths of said adapter tubes.

4. An exhaust header according to claim 1 wherein said projectingportions of said downstream ends project different predetermineddistances into said chamber.

5. In an exhaust header for receiving gases from the exhaust ports of anengine, wherein said header includes a collector having an elongatedinternal chamber, and further includes a plurality of main tubesdefining a corresponding plurality of air columns and adapted forconnection at their upstream ends to separate ones of the exhaust ports,the improvement comprising:

a plurality of adapter tubes of diflFerent lengths; and coupling meansconnecting said adapter tubes to one extremity of said collector and tosaid main tubes, said adapter tubes being located within said chamber,and forming a continuation of said main tubes, the

axes of said adapter tubes being generally parallel to the axis of saidchamber.

6. The exhaust header improvement according to claim 5 wherein saidcoupling means includes: mating flanges on said main tubes and saidadapter tubes; and means detachably fastening together said flangeswhereby said adapter tubes can be quickly attached to said main tubes toadjust the lengths of said air columns according to the lengths of saidadapter tubes.

7. The exhaust header improvement according to claim 5 wherein saidadapter tubes are immediately adjacent one another.

8. The exhaust header according to claim 1 and including a conduit incommunication with said internal chamber and the atmosphere to therebyenable a flow of air into said internal chamber.

9. The exhaust header according to claim 8 and including means forfeeding combustible fuel into said internal chamber.

References Cited UNITED STATES PATENTS 2,940,249 6/1960 Gospodar -323,287,900 11/1966 Soltau 60-30 FOREIGN PATENTS 182,583 12/1954 Austria.971,405 9/1964 Great Britain.

CARLTON R. CROYLE, Primary Examiner DOUGLAS HART, Assistant Examiner US.Cl. X.R. 181-40, 46

